Near-Infrared Spectroscopy Patterns as Indicator of Perioperative Stroke in Acute Type A Aortic Dissection.

Area of Science:

• Cardiovascular Surgery
• Neurology
• Medical Monitoring Technologies

Background:

• Neurologic complications are a significant cause of morbidity following acute type A aortic dissection (ATAAD) surgical repair.
• Near-infrared spectroscopy (NIRS) is a noninvasive tool for monitoring cerebral oxygenation during cardiopulmonary bypass.
• The predictive value of NIRS for perioperative stroke in ATAAD repair is not well-defined.

Purpose of the Study:

• To evaluate the utility of intraoperative near-infrared spectroscopy (NIRS) in predicting perioperative stroke after surgical repair of acute type A aortic dissection (ATAAD).
• To analyze the association between cerebral regional oxygen saturation (crSO2) values, NIRS signal variability, and stroke occurrence.

Main Methods:

• Retrospective cohort study of 175 patients undergoing ATAAD repair (2015-2023).
• Analysis of intraoperative NIRS data (crSO2, signal variability) at key timepoints.
• Stratification of patients based on perioperative stroke occurrence and comparison of demographic, anatomic, and NIRS variables.

Main Results:

• Patients with stroke had significantly lower minimum NIRS values during deep hypothermic circulatory arrest (DHCA).
• Increased NIRS signal variability and blunted recovery post-DHCA were observed in the stroke group.
• Lower cerebral oxygenation (crSO2 < 50%) and right common carotid artery dissection were more prevalent in patients with stroke.

Conclusions:

• Cerebral desaturation and NIRS signal instability during DHCA are significantly associated with perioperative stroke in ATAAD repair.
• Intraoperative cerebral oximetry, using NIRS, has prognostic value for identifying patients at risk of stroke.
• These findings support the use of NIRS to detect critical ischemic thresholds and monitor perfusion patterns during ATAAD surgery.